138244481 has 2 divisors, whose sum is σ = 138244482. Its totient is φ = 138244480.

The previous prime is 138244471. The next prime is 138244507. The reversal of 138244481 is 184442831.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 80712256 + 57532225 = 8984^2 + 7585^2 .

It is an emirp because it is prime and its reverse (184442831) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 138244481 - 2²² = 134050177 is a prime.

It is a super-2 number, since 2×138244481² = 38223073053918722, which contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (138244411) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 69122240 + 69122241.

It is an arithmetic number, because the mean of its divisors is an integer number (69122241).

Almost surely, 2^138244481 is an apocalyptic number.

It is an amenable number.

138244481 is a deficient number, since it is larger than the sum of its proper divisors (1).

138244481 is an equidigital number, since it uses as much as digits as its factorization.

138244481 is an evil number, because the sum of its binary digits is even.

The product of its digits is 24576, while the sum is 35.

The square root of 138244481 is about 11757.7413222098. The cubic root of 138244481 is about 517.0699123655.

The spelling of 138244481 in words is "one hundred thirty-eight million, two hundred forty-four thousand, four hundred eighty-one".